Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	$ 258,699	$ 245,414	$ 770,285	$ 731,499
Costs and expenses:
Service costs (exclusive of depreciation and amortization)	106,127	101,208	316,015	302,738
Selling, general and administrative expenses	50,600	47,735	145,701	136,373
Management fee expense	5,350	4,750	15,450	14,250
Depreciation and amortization	37,254	36,000	108,157	108,126
Operating income	59,368	55,721	184,962	170,012
Interest expense, net	(19,240)	(23,639)	(59,781)	(71,374)
Gain (loss) on derivatives, net	4,365	(4,886)	(4,313)	1,165
Loss on early extinguishment of debt (Note 6)			(1,156)
Other expense, net	(383)	(361)	(1,297)	(897)
Net income	44,110	26,835	118,415	98,906
Dividend to preferred members (Note 7)	(4,500)	(4,500)	(13,500)	(13,500)
Net income applicable to member	$ 39,610	$ 22,335	$ 104,915	$ 85,406